Tool
IU to mcg, and the other label units
Since the 2016 labelling rule, Supplement Facts panels give vitamin D in micrograms (IU optional, in brackets), vitamin A in mcg RAE, vitamin E in mg alpha-tocopherol and folate in mcg DFE. Older labels used IU. Each factor here is quoted with its source.
Common vitamin D amounts
| IU | mcg |
|---|---|
| 400 | 10 |
| 600 | 15 |
| 800 | 20 |
| 1,000 | 25 |
| 2,000 | 50 |
| 4,000 | 100 |
| 5,000 | 125 |
| 10,000 | 250 |
| 50,000 | 1,250 |
See where an amount sits among products with the dose checker, or vitamin D across all products.
Why there is no single IU factor for vitamins A and E
An IU of vitamin A or E stands for a different weight depending on the form (retinol or beta-carotene; natural or synthetic tocopherol, and which ester). The regulation (21 CFR 101.9(c)(8)(iv)) defines the new units by form, as in the converter above, and the label names the form. To compare an old IU label with a new one, find the form on the label first.